1. Field of the Invention
The present invention relates to a suspension device for use on a motor vehicle or the like.
2. Description of the Relevant Art
Most damper assemblies found in recent suspension devices for use on motor vehicles or the like comprise a combination of a hydraulic damper and a coil spring. The spring constant of some of these damper assemblies can be varied by adjusting the length of the spring. When the motor vehicle with such a damper assembly runs from a paved road into rough terrain, the spring constant of the damper assembly is varied for a harder suspension setting.
The coil spring is disposed around the hydraulic damper. Therefore, the diameter of the entire damper assembly is large. If such a damper assembly is incorporated in a double-wishbone suspension, the damper assembly tends to interfere with the upper arm of the suspension to a greater extent.
One solution to such interference would be to position a leaf spring, for example, separate from the damper, between the wheel and the vehicle body. The leaf spring would extend transversely of the vehicle body and have its outer end supporting the wheel and its inner end fixed to the vehicle body for giving the wheel vertical resiliency. Preferably, the spring constant of a damper assembly of this design should also be variable. This requirement could be met by employing a mechanism for shifting the point where the inner end of the leaf spring is attached to the vhicle body in the transverse direction of the vehicle body and then fixing the point for thereby adjusting the effective length of the leaf spring. Such a mechanism would however be highly complex.
The present invention has been made in an effort to solve in a simple practical manner the aforesaid problem of the conventional suspension device having a damper assembly comprising a coil spring and a damper.